SeasonMapAlter do Chão vs Rio de Janeiro: which is better, month by month
Rio de Janeiro beats Alter do Chão in 7 of 12 months — its lead peaks in April (83 vs 58) — while Alter do Chão wins August and October; they are within 3 points in July, September and November.
Each place is scored under the lens that suits its type. Comfort is SeasonMap's 0–100 estimate from ERA5 climate normals, not a forecast.
Alter do Chão vs Rio de Janeiro — all 12 months
| Month | Alter do Chão | Rio de Janeiro | Winner | Gap |
|---|---|---|---|---|
| January | 61Csweltering, soaked, clean air | 71Bsweltering, soaked, muggy air | Rio de Janeiro | 10 |
| February | 59Dsweltering, soaked, clean air | 73Bsweltering, soaked, poor air quality | Rio de Janeiro | 14 |
| March | 57Dsweltering, soaked, clean air | 79Bsweltering, soaked, muggy air | Rio de Janeiro | 22 |
| April | 58Dsweltering, soaked, clean air | 83Ahot, rainy, muggy air | Rio de Janeiro | 25 |
| May | 65Csweltering, soaked, clean air | 86Ahot, a little rain, muggy air | Rio de Janeiro | 21 |
| June | 80Asweltering, soaked, clean air | 86Awarm, a little rain, muggy air | Rio de Janeiro | 6 |
| July | 85Asweltering, rainy, clean air | 87Awarm, a little rain, muggy air | Tie | 2 |
| August | 88Asweltering, a little rain, clean air | 83Awarm, a little rain, muggy air | Alter do Chão | 5 |
| September | 87Asweltering, a little rain, clean air | 88Ahot, a little rain | Tie | 1 |
| October | 82Asweltering, rainy | 78Bhot, rainy, muggy air | Alter do Chão | 4 |
| November | 77Bsweltering, rainy | 77Bhot, soaked, muggy air | Tie | 0 |
| December | 63Csweltering, soaked, muggy air | 75Bsweltering, soaked, muggy air | Rio de Janeiro | 12 |
A month is a tie when the two are within 3 points. The widest gap is April (58 vs 83). Tap a month for that month's temperature, rain, humidity and air quality side by side.